The contact closure sensor bridge has four connectors that can be used to monitor up to four pieces of equipment with dry contact.
Different pieces of equipment have different ways to expose a contact closure signal. The Senseware Contact Closure Sensor Bridge can support different configurations that can be set up through the configuration page.
1. The equipment has a simple dry contact output
In this case, the output consists of a dry contact relay that will relay the 3.3V provided by the contact closure sensor bridge when an event is detected. Connect one the + connectors of the bridge to the + connector of the equipment and the corresponding - connector of the bridge to the - connector of the equipment. The bridge will be operating in this mode if 'Bridge Voltage Source' is selected on the configuration page.
Examples: This setting has to be selected if you are using a door contact closure sensor or a water leak detection sensor.
2. The equipment is providing its own contact closure signal
In this case, the equipment is providing its own positive contact voltage. Connect the equipment signal wire to one of the - connectors on the bridge and the corresponding + connector to the ground of the equipment. The bridge will be operating in this mode if 'External Voltage Source' is selected on the configuration page.
Note: if the voltage of the signal provided by the equipment is above 5V, please contact Senseware before connecting the meter as it can damage the sensor bridge.
Note: it is not recommended to use a Node on battery if you are using a contact closure sensor bridge in this mode.
3. The equipment contact closure signal is switching to ground
In this case, the equipment is providing a contact closure signal switching to ground when an event is detected. Connect the equipment signal wire to one of the - connectors on the bridge and the corresponding + connector to the ground of the equipment. The bridge will be operating in this mode if 'Contact to ground' is selected on the configuration page.
Once the contact closure sensor bridge is properly wired, connect it to an available port on the node and power the node. The LED associated with each piece of equipment will turn on if the dry contact is closed, and then turn off once the dry contact is open.
Power: 3.3V DC from node or gateway via micro-USB connector
Inputs: 4 dry contact signals (provides 3.3V DC to equipment)
Bridge Output: 4 open/close signals
Size (inches): 2.1 x 2.1 x 0.4
Weight (ounces): 0.8
Note: If you have a contact closure bridge that has four separate connectors as depicted on the image below, the only mode supported is 'Bridge Voltage Source'.